Self-contained electro-hydraulic actuating device



R. LU ClEN March 16, 1965 SELF-CONTAINED ELECTRO-HYDRAULIC ACTUATING DEVICE Filed June 3, 1963 UMP United States Patent 3,173,257 SELF-CONTAINED ELECTRO-HYDRAULIC ACTUATING DEVICE Ren Lucien, Neuilly-sur-Seine, France, assignor to Societe a Responsabilite Limitee: Recherches Etudes Production R.E.P., Paris, France, a corporation of France 7 Filed June 3, 1963, Ser. No. 285,021 Claims priority, application France, June 2, 1962, 899,510, Patent 1,337,263 3 Claims. (Cl. 6052) The invention. relates to an electro-hydraulic device permitting the operation of a servo-control of any kind, for example of an isolating gate-valve, by means of a double-acting jack supplied from an electro-pump.

In this electro-hydraulic actuating device, the jack and the electro-pump with its associated structure form a self-contained, portable unit that can be brought to and mounted on the apparatus to be controlled exactly as it is, Furthermore, the hydraulic supply and safety devices are combined together in an adaptable unit, which can be suitably orientated irrespective of the position which the apparatus to be controlled imposes on the jack.

In addition, by virtue of this adaptable feature, it is possible by simple assembly to install and control jacks of different sizes, without any modification of the device.

The electro-hydraulic device is illustrated in the accompanying drawings, in which:

FIG. 1 is a general view in elevation of the electrohydraulic actuating device.

FIG. 2 shows to a larger scale and in a relative arrangement arbitrarily chosen for convenience of the description, the jack, the electro-pump with its accessories and the hydraulic circuit.

IiIG. 3 is a view in cross-section of a detail, to a larger sca e.

A support 1 which is fixed on the apparatus to be controlled (not shown) comprises two securing flanges 1a, 1b at right angles. One of these, receives a double-acting jack 2, the rod T of which will be coupled to that of the apparatus to be controlled. The other flange 111 has secured thereto a unit casing 3 which houses or supports all the other hydraulic members. This arrangement makes it possible, by virtue of the two degrees of freedom of the attachment, to give the casing the most suitable orientation, irrespective of the orientation of the jack.

The latter is provided with a mechanical locking device for its rod in its two extreme positions. This locking device may be of any appropriate kind, for example of the claw type.

The jack has the particular feature that its piston 4 is coupled to the rod T through the intermediary of a spring 5, advantageously formed by a stack of elastic washers. This coupling otters the two-fold advantage, on the one hand of maintaining on the rod, locked in its fully out position (the case of FIG. 2), a continuous force which ensures rigidity of the control, and on the other hand of permitting a certain latitude in the final position of the rod, which is often useful, especially in the control of wedge gates, when good fluid-tightness is required or when possible wear of the seats of these gates must be taken into account.

At each of its extremities, the jack is provided with an end-of-travel contact switch 6a6b, such as a microswitch the function of which will be explained later.

The two chambers of the jack are connected by conduits 7a-7b to the electro-hydraulic members from which they are supplied, and which are contained in the unit casing 3 or are supported thereby.

An electric motor M adapted for rotation in both 3,173,257 PatentedMar. 16, 1965 directions, is coupled to the switches 6a-6b, if necessary through the intermediary of a control relay. The motor M drives a pump 8 which is reversible, that is to say, when the direction of rotation of the pump is reversed, the delivery outlet becomes the suction inlet and vice versa. This pump sucks the liquid from one chamber of liquid to the jack and delivers it into the other chamber. However, this supply of liquid to the jack is controlled by various members which will now be described with reference to FIGS. 2 and 3.

In order to correct the effect of the difference in the sections of the two chambers of the jack and possible leakages of the pump, two compensating 'valves 9a-9b are mounted respectively on each of the two circuits of the pump. Their function is to evacuate the excess or to ensure the complete filling of the liquid, depending on the operation effected. Each of these compensating valves is composed of a jacket 10 movable inside a body 11. In this jacket, provided with an opposing spring, there slides a diaphragm valve 12. A loss of pressure causes a displacement of the jacket, which compresses its spring and then closes return-circuit orifices 13 formed in the body 11. In the opposite direction, the flow of liquid passes freely through the valve 12, and the orifices 13, uncovered by the jacket, allow the excess liquid to pass, depending on whether, at the moment considered, the evacuation of the large chamber or of the small chamber of the jack is being etfected.

Excess-pressure valves 14a-14b protect each of the two circuits.

For the case where an unexpected stoppage of the electric motor or of the pump occurs, the device comprises an emergency hand-pump 15, which has two separate deliveries 15a-15b corresponding respectively to the chambers of the jack. A manual change-over switch 16 permits, through the intermediary of an eccentric 17, the closure of one or the other of two non-return valves 18a-18b, which are both held open during normal workmg.

Finally, a third excess-pressure valve 19, placed between the non-return valve 18b and the rod entry chamber of the jack, controls the pressure developed by the emergency hand-pump 15. This pressure may be substantially higher than that developed by the electro-pump, thus permitting a greater force to be applied during emergency.

The operation of the electro-hydraulic actuating device according to the invention is effected as follows:

Assuming the piston 4 to be for example in the position in which the rod T is fully extended as shown in FIG. 2, actuation of the electro-pump in the appropriate direction first acts on the pressure fluid to cause release of the piston, and thereafter displacement of the latter to its opposite end-of-travel position whereat the piston is locked. The locking of the piston results in the stopping of the motor by the actuation of the end-of-travel switch 6a.

What I claim is:

1. An electro-hydraulic actuating device comprising a self-contained portable assembly forming a single unit adapted to be associated with a device to be controlled, said assembly comprising a double acting jack including a piston rod adapted for being connected to the device to be controlled, said jack including a piston defining two isolated and opposed chambers in the jack, means including an elastic connection between the rod and the piston, said elastic connection comprising a stack of elastic washers, the assembly further comprising a reversible motor, a pump driven by said motor, a hand pump and a hydraulic circuit connecting the motordriven pump, the jack and the hand pump, said hydraulic circuit including two compensation valves to correct the the jack and of possible leakages from the pumps, and two non-return valves permitting manual change Over of delivery to said jack from said pump driven by the motor and said hand pump, said hydraulic circuit further including a pair of conduits extending from the motordriven pump to the separate chambers of the jack to alternate the supply of pressure fluid to the chambers of the jack in accordance with the direction of rotation of the motor, and limit switch means in each chamber of the jack for terminating operation of said motor when the piston reaches end positions in the jack.

2. An electro-hydraulic actuating device according to claim 1, wherein the hand pump develops a pressure which is greater than the pressure produced by the motordriven pump.

4 3. An electro-hydraulic actuating device according to claim 1, wherein said hydraulic circuit comprises an excess-pressure valve for controlling the pressure that has been developed by the hand pump.

References Cited by the Examiner UNITED STATES PATENTS 1,616,841 2/27 Beebe 60-52 X 2,255,878 9/41 Dilley 6052 X 2,349,244 5/44 Brown 92--27 X 2,927,429 3/ 60 Carlson 6052 2,944,525 7/60 Fagge 60--97 X JULIUS E. WEST, Primary Examiner.

EDGAR W. GEOGHEGAN, Examiner. 

1. AN ELECTRO-HYDRAULIC DEVICE COMPRISING A SELF-CONTAINED PORTABLE ASSEMBLY FORMING A SINGLE UNIT ADAPTED TO BE ASSOCIATED WITH A DEVICE TO BE CONTROLLED, SAID ASSEMBLY COMPRISING A DOUBLE ACTING JACK INCLUDING A PISTON ROD ADAPTED FOR BEING CONNECTED TO THE DEVICE TO BE CONTROLLED, SAID JACK INCLUDING A PISTON DEFINING TWO ISOLATED AND OPPOSED CHAMBERS IN THE JACK, MEANS INCLUDING AN ELASTIC CONNECTION BETWEEN THE ROD AND THE PISTON, SAID ELASTIC CONNECTION COMPRISING A STACK OF ELASTIC WASHERS, THE ASSEMBLY FURTHER COMPRISING A REVERSIBLE MOTOR, A PUMP DRIVEN BY SAID MOTOR, A HAND PUMP AND A HYDRAULIC CIRCUIT CONNECTING THE MOTORDRIVEN PUMP, THE JACK AND THE HAND PUMP, SAID HYDRAULIC CIRCUIT INCLUDING TWO COMPENSATION VALVES TO CORRECT THE EFFECTS OF THE DIFFERENCES OF SECTIONS OF THE CHAMBERS OF THE JACK AND OF POSSIBLE LEAKAGES FROM THE PUMPS, AND TOW NON-RETRUN VALVES PERMITTING MANUAL CHANGE OVER OF DELIVERY TO SAID JACK FROM SAID PUMP DRIVEN BY THE MOTOR AND SAID HAND PUMP, SAID HYDRAULIC CIRCUIT FURTHER INCLUDING A PAIR OF CONDUITS EXTENDING FROM THE MOTORDRIVEN PUMP TO THE SEPARATE CHAMBERS OF THE JACK TO ALTERNATE THE SUPPLY OF PRESSURE FLUID TO THE CHAMBERS OF THE JACK IN ACCORDANCE WITH THE DIRECTION OF ROTATION OF THE MOTOR, AND LIMITING SWITCH MEANS IN EACH CHAMBER OF JACK FOR TERMINATING OPERATION OF SAID MOTOR WHEN THE PISTON REACHES END POSITIONS IN THE JACK. 